Cartridge-powered piston type tool



NoN cow RVR. HAsKELL ErAL CARTRIDGE-POWERED PIs'roN TYPE 'rooL Original Filed May l0, 1955 Oct. 4, 1960 S SNS 2 SER n@ 8 3N S. mm mm Plc-HARD E.EYA Ns. By PAUL A. KErcHPEL Je.

Lw.: B CoN/vof?.

z l mflf -2 Arron/m Oct. 4, 1960 P. R. HASKELL EVAL 2,954,759

CARTRIDGE-POWERED PIs'roN TYPE Toor.

2 Sheets-Sheet 2 Original Filed May l0, 1955 INVENTORS. PHN. l P RHAsKE/J... Elch/AED EEvA/vs. By /q uz. A KETCHPEL de.

Patented Oct. 4, 1960 flee CARTRlDGE-POWERED PISTON TYPE TOOL Original application 'May 10, '1955, Ser. No. 507,281. and this application July 26, 1957, Ser. No.

1 Claim. (Cl. 12S-24) This invention pertains to improvements in explosively actuated or cartridge powered tools, and provides a tool of this type of unique construction which is characterized by eXtreme compactness, lightness in weight and ease of manipulation with a minimum of effort, and which furthermore is substantially foolproof.

This application is a division of our copending application Serial No. 507,281, filed May 10, 1955.

In its various modifications the tool of the invention is adapted for performing a wide variety of work functions, such as the cutting of conduit, bar stock and heavy cable, etc., the punching of holes, riveting, the swaging of terminals or sleeves on electrical cables for terminating or uniting the same, the uniting of electrical conduit sections by means of an interposed coupling member, as well as the securing of threaded members on electrical conduit terminations, etc.

-The tool of the invention comprises in its essentials and in accordance with a preferred modification, an elongated frame member of steel comprising a tubular or barrel section terminating -at one end in a hook-like retainer arm of substantially C-shaped configuration for mounting a work piece to be operated upon. Within the barrel section is slidably displaceable a piston which mounts on its forward end a work tool, such as a cutter blade, hole puncher, cable swager, riveting plunger, etc. The tubular section of the frame is of reduced aperture at its muzzle end to provide a shouldered impact face for arresting forward motion of the piston thereat. The muzzle end is, in addition, appropriately apertured for passage of the work tool therethrough to work engaging position with a work piece held in the retainer arm.

One of the novel features of the invention resides in the termination of the rear end of the piston in a protuberance of relatively small bore as compared to the piston proper or barrel which protuberance seats, in the tiring position, in a bore of substantially corresponding diameter formed in the inner end of the barrel plug and which has access to the cartridge chamber through the outlet apertures of smaller bore above mentioned. This relatively small bore in which the protuberant piston terminus seats, is of such diameter and length as to assure complete burning of the powder charge before this piston protuberance passes out of the conforming barrel plug bore, and thus assures that the powder charge will not snuff out.

. In the drawings: Y

Figure 1 is a longitudinal sectional elevation through the entire tool assembly, and showing the tool in condition for firing. Figures 2 and 3 are views similar to Figure 1, but subsequent to firing and showing the advance of the piston and cutter tool assembly in successive stages to the cutting position.

Figure 4 is a partial showing, similar to Figure 1, but

illustrating the tool `in the cartridge ejecting or loading condition. I Referring to the drawings, the conduit-cutting modilication of the invention shown therein comprises a frame, identified generally by numeral 1, consisting of a tubular frame portion 2 extending from the breech end at the left to the muzzle end at the right, and a C-frame extension comprising a work support 3 in general longitudinal alignment with the frame portion 2 and connected therewith by a curved shank 3a. The breech end of the frame portion is of slightly enlarged bore as compared to the muzzle end of the frame portion 2 and thus provides a shoulder at 4, against which a relatively short sleeve barrel 5 is held by means of a barrel plug 6, inserted in the breech end of the frame. The barrel plug is locked in the position shown by a cylindrical cartridge chamber plug 7, which extends transversely of the barrel axis through suitable holes 8, 9 drilled in the barrel plug and the breech end of the frame portion 2, respectively. The cartridge chamber plug 7 is provided with an enlarged head 10 which seats in a counterbore 11 of the barrel plug, thus to maintain the assembly locked in position as shown in Fig. 1.

The mouth of the chamber plug is radially slotted to receive an ejector (to be described), and to locate chamber plug 7 in proper longitudinal and radial position in the bores 8, 9, the cylindrical wall of the plug is notched for reception of a pin 1'2, backed by a small compression vspring 13, mounted in an axial bore 13a of the barrel plug 6. A

In the firing position shown in Fig. 1, a piston 14 is slidably disposed in the sleeve barrel 5, and towhich is secured a cutter blade 15 positioned in advance of the piston in the frame portion of smaller inside diameter. The cutter blade is slidable in grooves 16, 17 extending along the upper and lower portions of the frame barrel, these grooves being formed as explained below.

The cutter assembly 15 shown as a cutter blade is secured to or formed integral with a shank 18, which extends through a central sleeve member 18h of the piston 14 and is secured to the piston by means of a piston cap 19 threaded onto the breech end of the shank 18.

For purposes above noted, to be explained in detail below, and as shown in the drawings, the breech end of the piston cap 19 terminates in a protuberant extension 20 of considerably smaller diameter than the piston 14, which extension in the action or firing position, rests in a conforming bore 20a drilled in the inner end of the barrel plug 6.

Also in the action or firing position of Fig. 1, the piston and cutter blade assembly 14, '15, is resiliently held in place by means of a resiliently mounted detent Zilb which engages the upper edge of -the cutter blade as shown.

The cartridge chamber 7 has formed in the upper portion thereof a bore 21 for insertion of a blank cartridge, as at 2.2, the cavity below the cartridge forming an cxplosion chamber which has access through aligned openings in the sidewall of the chamber plug and the forward end of the barrel plug, as at 22a, 23, to the bore 20a of the barrel plug.

Thus when the cartridge is red, the piston and cutter assembly 14, 15, is impelled progressively forward as illustrated in Figs. 2 and 3, until the pointed end of the cutter blade has advanced to the position shown in Fig. 3 to sever the conduit. The piston and cutter assembly is thereupon brought to rest by engagement of the forward end of the piston 14 with a shouldered impact face 24, Fig. l, of conforming configuration formed at the muzzle end of the tubular frame section 2, at which Vthe bore is tapered to an outlet passage 25 of relatively small bore through which the explosion gases escape as explained below. The muzzle end o-f the -frame is also vertically slotted, to permit advance therethrough of the cutter blade to the conduit cutting position of Fig. 3.

The tubular frame sectionZ is longitudinally slotted through its upper surface. Mounted in this slot and partially closing the same is an insert member 38, Fig. l. This insert member is secured to the frame by means of screws as at 39, which extend through holes in the sidewall of frame 2 and into threaded'engagement with the insert member 38, thereby clamping the insert member to the frame. For additional strength the screws ,39 are supplemented by dowel pins 41, which also extend as through the sidewall of the frame section 2 and into suitable apertures provided in the insert member 5S, these dowels frictionally engaging the frame and insert member in a tight fit.

The insert member 38 is of substantially rectangular cross section, as shown in Fig. 8, except for a depending liange, whereby the insert and the oppositely disposed surface portion of the frame 2 provide a l0ngi tudinally extending grooved recess 16 in which the upper edge of the cutter blade is slidably guided. Diametrically opposite to the grooved recess 16 thus provided, there iS also machined in the frame 2 a corresponding groove 17, for slidably guiding the lower edge of the cutter blade 15.

The frame 1 is provided with a cover o-r carriage 50 having in end view, a relatively flat C-shaped configuration, with turned in lower lateral edges. The frame section 2 is correspondingly grooved along the upper edges of its opposite outer sidewalls, whereby the cover may be slid endwise onto the frame in vertically locking engagement therewith.

Mounted on the breech end of the cover is the firing unit 55', Fig. l. Mounted adjacent thereto is the cross slide protective device 56 which is transversely adjustable to locking, ejecting and ring positions, and which prevents firing except when adjusted to the position last mentioned. Resiliently mounted on the muzzle end of the cover is a clamping device 57 which clamps the conduit to be cut in the C terminus or work support 3 of the frame when the cover is longitudinally positioned with respect to the frame as shown in Fig. 1.

For limiting the forward displacement of the cover 50 with respect to the frame 1, the insert 38 is provided with a raised portion or shoulder 60 at the muzzle end of the frame section 2, Fig. 1. When the cover is advanced to the position of Fig. 1, this shoulder is engaged by a pin 61 extending transversely along the under side of the cover 50, and mounted in a bore 62, Fig. l, drilled through the sidewalls of the cover.

For returning the piston 14 from the impact face 24 of the frame barrel 2, against which the piston rests after tiring as above explained, a piston return bolt 63 is tapped vertically through the cover as shown in Fig. 1 with the lower end of this bolt projecting into the slot 3'7 of the frame for a sufficient depth as shown in Fig. 4, to engage the piston as the cover 50 is displaced to the left from the firing position of Fig. 1, to the cartridge ejecting position of Fig. 4. It will be noted, referring to Fig. l, that the slot 37 extends at the muzzle end of the frame barrel 2, beyond the piston impact face 24, and is thus protected from impact by the piston even if the shoulder 24 is set back by repeated impact.

Referring to Fig. 3, a shallow axially extending slot 65, is provided in the upper face of the frame section 2 near the breech end, in which is mounted an Velongated cartridge ejector 66, which pivots on a pin 67 retained in a transverse bore 68 of the frame. The ejector 66 is actuated by displacement of the cover 50 as follows: As the cover is retracted from the firing position of Fig. l to the cartridge ejecting position of Fig. 4, the pin 61 mounted on the under side of the cover, engages a concave cam face 69 of the ejector and rotates it clockwise to the canted position shown in Fig. 4, to eject the cartridge shell 22, through an opening formed in the cover of the cross slide 56. The :under face of the frame cover S0' is provided with a sloping ramp, as at 71, to permit of this actuation of the ejector. With the cover in the position of Fig. 4, a new cartridge may be inserted through the cross slide opening, until the rim thereof engages the cartridge ejector end 72 of the ejector, whereupon the frame cover 50 is returned to the position of Fig. 1. As the cover is thus moved into position a second sloping ramp provided on theopposite under side of the cover, as at 73, engages the rim of the cartridge and seats it in the cartridge chamber cavity 28 with the shell rim iiush with the upper edge of the cavity as shown in Fig. l, while at the same time returning the ejector 66 to the cartridge seating'position of Fig. 1 as the frame cover pin 61 rides off the cam face 69. In order to provide for seating of both the cartridge shell 22 and the ejector 66 llush with the upper surface of the chamber plug 7, this surface is peripherally recessed, as at 78a and radially slotted, as at 70b, Fig. 1, 4appropriately to seat the shell rim and ejector, respectively.

Referring to Fig. 1, the ring unit 55 comprises a housing 74, secured to the frame cover 50, by means of screws. The housing is drilled for axially displaceable reception of a tiring bolt or hammer having an intermediate portion 76 -ofenlarged diameter which is slidably displaceable in the frame bore 7611 and from one end of which extends a hammer terminus 77 of smaller diameter, sleeved through a hammer spring 78, housed in an openended sleeve-like retainer 79, the inner end of which is threaded to the housing as at 79h.

From the opposite end of the enlarged hammer portion 76, there extends a second hammer terminus 80 having a flatV under face 81, Fig. 22, which terminates adjacent the enlarged hammer portion 76, in a stepped cam face 82 for actuating a tiring pin 83. Interposed in the housing bore between the end of the shank 80 and the bore terminus, is a relatively light spring 84 which is compressed in the firing movement of the hammer and thereafter returns the hammer to normal uncooked position with the shouldered end of hammer enlargement 76 contacting the spring 78 at the housing abutment.

As shown in Fig. 1, the at under face 81 of the terminus 80, normally bears against the enlarged head of the tiring pin 83, which latter is positioned in a bore extending through the housing 74V and into the frame cover 50. The lower end of the firing pin is of reduced diameter as shown and sleeves through a tiring pin spring 85, which is retained in position between the enlarged head of the firing pin and the reduced diameter base of the frame cover aperture, through which the tapered lower end of the tiring pin extends into engagement with the rim ofthe cartridge 22, when the tool is loaded'in the manner illustrated;

Referring more particularly to Fig. 1, the conduit to be cut, is positioned in the hook-like retainer arm 3 of the tool frame, and against a pair of arcuate bushings as at 151, these bushings being secured to the rear of the retainer arm by means of bolts 153, 154, which extend through the rear of the retainer arm and thread into the bushings.

As above stated, there is resiliently mounted on the frame cover 50 at the muzzle end thereof, a clamping assembly 57, which includes a metal clamping member 157 of substantially U-shaped configuration viewed in end elevation, and which spans the frame cover 50 and is formed at its opposite ends with turned down or depending arms, as at 159. These armshave the-configuration, viewed in side elevation, best shown in Fig. 1, and are provided with arcuately curved lower front edges adapted to engage the surface of the conduit 150 and thereby force the same against the bushings 151, 152. The clamping member 157 is loosely secured to the frame cover 50 by means of a guard screw 161 which passes through an oversize central aperture of the clamping member, and is threaded into the frame 50. Adjacent the guard screw the clamping' element is provided with a struck-up, apertured portion, as at 162, in

which is mounted a resilient cushioning element 163 of rubber or equivalent, which rests ou the top of the frame cover 50, and thus resiliently supports the clamping member 157 in spaced relation to the frame cover 50. As the frame cover is moved to the firing position of Fig. i, the arcuate edges 160 of the clamping element arms as at 159, engage the conduit 150 and force the same against the bushings as at 151, and in so doing rotate 4the clamping element 157 clockwise about the axis of support provided by the guard screw 161, whereby the cushioning element 163 is flattened somewhat from the position of Fig. l to that of Fig. 3, thus resiliently clamping the conduit 150 in position in the manner shown in Fig. 3.

To further assist in the supporting and clamping of the conduit, there is mounted at the base of the frame arm 3, an arcuately surfaced segment member 164, held in position by ya bolt 165 threading into the base of the frame arm 3, this segment being centrally slotted to provide passage of the cutter blade past the same. The arcuate face 167 of this segment supports the underside of the conduit in the manner best illustrated in Fig. 1. After the conduit is severed by the cutter blade in the manner illustrated in Fig. 3, retraction of the frame cover 50 of course, retracts the clamping element 157 along with it, thus to permit of inserting a new conduit section in the frame arm 3 to be cut.

Referring to Fig. 1, it will be observed that when the cover 50 is advanced to the ring position, the forward end of the cover covers the open -C of the hooklike retainer arm 3, so that the cover is thus in this closure position whenever the conduit is to be severed. As thus closed the cover insures that the conduit cannot be half-in and half-out of the die bushings 151, when the tool is fired. The frame cover 50 as thus closed automatically and safely covers the region into which the shear cutout conduit chips are thrown, and permits them to be dumped out when the cover is open. The operator is thus shielded against ilying chips of metal.

The tool is provided with a handle 200 of wood, hard rubber or equivalent, which is assembled on the under side of the tubular frame section 2, by means of bolts, as at 201, 202, threaded into the frame.

Mention was made above of the fact that the terminal portion of the steel piston cap 19 is of considerably reduced diameter as compared to the bore of the sleeve barrel 5 and the piston 14, and that this reduced diameter terminus of the piston cap iits into a corresponding bore 20a, in the forward end of the barrel plug 6 through which the explosion chamber 21 has access to the bore 20a through the apertures 23a, 23 in the cartridge chamber and barrel plug, respectively. The significance of this is that experimental tests have shown that with a barrel of relatively large bore, such as that of the barrel 5, the initial expansion volume for the burning powder from the cartridge 22 is provided at so great a rate, as the piston moves forward, that combustion of the powder is irregular. Powder of sufficiently fine granulation to be quick enoug for a barrel of the relatively large bore of the barrel 5, is not commercially available, and would be dangerous to handle industrially even if it were. The smaller diameter protuberance extending from the piston cap into the barrel plug bore 20a, provides a smaller bore diameter during the period of powder burning as the piston initially moves forward, and a larger diameter bore during powder gas expansion, the latter as the piston cap protuberance moves out of the barrel plug cavity to permit of an expansion of the gases into the larger bore of the barrel 5. It will further be noted in this regard, that this protuberance 20 on the piston cap is nevertheless of considerably larger bore than the diameter of the shell 22 itself, and thus provides an initially exposed eiective piston area large enough to apply tremendous acceleration to the piston by the powder up to the time it is completely burned, but at the same time, does not permit the powder to snui ou by the pressure drop that might otherwise occur if the explosion chamber bore 21 has access directly to the large bore of the barrel 5. With the arrangement shown, it is not until the powder is completely burned that the large bore of the barrel 5 is uncovered, so that the gas, expanding, can act on the larger piston area during the remainder of travel. A large diameter piston has the distinct advantage in providing maximum expansion volume for powder gas in a tool of minimum length, such as that shown, A tool of the relative dimensions shown having a bore of about 1" for the barrel 5 and an effective length of the frame barrel of about 1% provides an explosion chamber which would be equivalent to a barrel of about 22" in length, provided the piston were of the same caliber as the shell.

What is claimed is:

In an explosively actuated device: a barrel of relatively large bore, a piston displaceable in said barrel, said piston having a cylindrical protuberant terminus of relatively small bore at its breech end, breech closure means for said barrel having a cylindrical cavity of relatively small bore complementary to said piston terminus for reception of the same in tiring position, a cartridge chamber disposed in said closure means, said chamber having access to said cylindrical cavity through a bore of substantially smaller diameter than said cavity, whereby discharge of said cartridge applies an initially large accelerating force to said piston, said cylindrical cavity being of such diameter and length as to assure substantially complete burning of the powder charge of said cartridge before said protuberant piston terminus is im-' pelled from said cavity.

References Cited in the le of this patent UNITED STATES PATENTS 1,569,153 Temple Jan. 12, 1926 1,824,457 Barlow Sept. 22, 1931 2,135,888 Febrey Nov. 8, 1938 FOREIGN PATENTS 169,919 Switzerland Sept. 1, 1934 

